assume cs:code

stack segment
	db 128 dup (0)
stack ends

code segment
start:	mov ax,stack
	mov ss,ax
	mov sp,128

	mov ax,0b800h
	mov es,ax
	mov ah,'a'
s:	mov es:[160*12+40*2],ah
	call delay
	inc ah
	cmp ah,'z'
	jna s

	mov ax,4c00h
	int 21h

delay:	push ax
	push dx
	mov dx,10h	;循环10000000h次,读者可以根据自己机器的速度调整循环次数
	mov ax,0
s1:	sub ax,1
	sbb dx,0
	cmp ax,0
	jne s1
	cmp dx,0
	jne s1
	pop dx
	pop ax
	ret

code ends
end start



